Something apparently existing, or existing in name, but having no real substance; anything without meaning or value; a chimera.
Originally in Carroll's Sylvie and Bruno referring to illusory fruit and flowers, and in one scene an illusory nursemaid..
Origin
Late 19th century; earliest use found in ‘Lewis Carroll’ (1832–1898), author, mathematician, and photographer (real name Charles Lutwidge Dodgson). A factitious word introduced by Lewis Carroll.